


The Doll Implant

by Pinbones



Category: Undertale (Video Game)
Genre: Begging, Coworkers in Science, Crying, Dollification, Ecto-Genitalia (Undertale), Feminisation, Forced Orgasm, Kidnapping, M/M, Pet Names, Praise Kink, Sans Has a Bad Time, Sanster, Unwanted Pleasure, gaster is a creep, misgendering Sans as female
Language: English
Status: In-Progress
Published: 2018-04-13
Updated: 2018-04-13
Packaged: 2019-04-22 11:46:03
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 1
Words: 3,320
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14307978
Author URL: https://archiveofourown.org/users/Pinbones/pseuds/Pinbones
Summary: Gaster leads Sans into the backroom after work. Unbeknown to Sans, this isn't just any experiment, and Gaster paralyses him and turns him into his own little sex doll.





	The Doll Implant

It was Friday, after hours at the lab.

Gaster led Sans into a back room where a table was set into the middle of the floor and a computer was stood beside it. "This should be an easy one, so long as nothing goes wrong."

"that's encouraging.” Sans shoved his hands in the pockets of his lab coat. “so, what exactly are we doing here, doc? another soul implant for Asgore?"

"Actually, no." Gaster switched on the little device in his hands. "Well... yes, it's an implant for your soul. But this one is different. It's nothing to do with the Barrier."

Sans eyed the little device. It didn't look normal, but Sans couldn't determine its function from just a glance. He shrugged. "okay. put her in."

“First, I'll need a few measurements. Stay still.” Gaster procured a length of measuring tape and took measurements of Sans's height, shoulder width, shoulder-to-hip as well as around his waist. Sans didn't bother asking what for. From the excited way Gaster took his measurements down, it was probably another lab coat or something.

Gaster rolled up the tape and stuffed it in his lab coat pocket. “Right... I'm done. Now for the implant.”

“'kay.”

Gaster gestured to the steel table.

"oh, come on, g. don't tell me i have to strip for this one?”

"Just remove your shirt and we'll be done soon."

"i thought you said this would take an hour?"

"The testing will take a while," Gaster said, with a glint of amusement in his eyes. “The implant won't take long to install.”

Grumbling, Sans shrugged off his lab coat and unbuttoned his shirt and let them fall to a heap on the floor. The cool lab air chilled his ribs but he wouldn't be on the table for long. He hopped his butt up onto the table and shuffled over. He laid down, hissing as the frigid steel contacted his spine.

Gaster extended a hand above his chest, waiting for Sans to summon his soul.

"er, doc? aren't you forgetting something?"

Gaster blinked and looked down at his bare, glove-less hands. "Ah – yes. Thank you, Sans." His voice was flat, almost displeased. Was he hoping Sans wouldn't notice? Gaster slipped on his gloves, the latex snapping against his forearm bones. Sans cringed at the sound.

Gaster held his hand over Sans's chest again and Sans summoned his soul over his chest. Gaster caught the soul and Sans shivered. He couldn't feel the contact, but he still felt strange. Something was different in the way Gaster was handling his soul today. The little device bleeped as Gaster turned it on. He held up a scalpel. "I'm making the incision now."

"right-o, doc."

“Normal protocol. Just relax.”

Sans couldn't help it, he went tense as the scalpel brushed his soul. He felt his soul tear open and he shuddered. Something definitely felt different this time.

The little device pressed into the split and Gaster gripped the soul in both hands, clasping it tightly. Sans felt the gash begin to reseal over the implant, leaving it inside.

Gaster released his soul. It floated over Sans's rib cage. There was a tiny shadow inside, which had to be the implant.

"are we done, doc?"

"Please stay on the table. It will make things easier."

"we're testing it right here? Aren't we going to the testing chambers?"

"No, not today. It's... staying off the record. It's more of a personal side project.”

"don't tell me you're working on another secret device? and you're testing it on me?"

Gaster didn't respond. He picked up a little remote control, as small as a presentation clicker. It probably was a modified presentation remote.

"am i the first test subject, doc?"

Gaster fiddled with the controls excitedly and didn't answer Sans's question.

"doc? g? doctor gaster? hey, dings, come on, don't leave me in the dark here –"

Gaster clicked it and Sans felt a tremor wrack through his bones. His mind became heavy, then incredibly light and airy. Sans laid still, feeling himself float on a wave of semi-consciousness and drift back to reality.

"fuck, g," Sans slurred. "you makin' me high."

"Do you feel high? Well, that's a nice side-effect for you."

The wave dipped and rose as he breathed.

Side-effect? So what else was happening?

Able to take only shallow breaths, Sans tried to sit up but couldn't move a single joint. He tried to move his hand but he couldn't twitch a finger. He couldn't even blink. "uh, doc?"

Gaster stood over him, looking immensely satisfied.

"uh... you didn't brief me right."

"Can you raise your arm, Sans?"

Sans tried. "uh. no. am i supposed to be able to?"

"Can you move at all?"

"no." Sans didn't like the look in Gaster's eyes. "doc, what's going on? you didn't tell me this would happen. did something go wrong?"

"No, Sans. Quite the opposite." Gaster lifted a hand and trailed a fingertip over Sans's soul. "In fact, it worked... perfectly." He lowered his hand onto Sans's rib cage, gently resting his fingertips across them.

"doc?"

"Honestly, I assumed you would lose your voice, but being able to hear you is better." Gaster leaned in.

Sans followed him with his eyes, the only things he could move. "this wasn't in the briefing."

"No, it wasn't." Gaster's latex-clad hand gripped Sans's sternum, fingers reaching in between his ribs. He leaned down.

“what are you doing?”

Gaster pressed his jaw to Sans's neck.

“gah–” Sans tried to move, tried to get away, to no avail. "gaster! what the fuck! what're you--?"

Something wet pressed to his vertebrae and he tried in vain to recoil. Stars above, was that his _tongue_?

"GASTER –" His shout was cut off by a gloved hand grabbing his jaw, startling him.

"Easy, Sans," Gaster whispered. "You can't resist any more, so don't try.”

 _shortcut_ , he thought desperately. _shortcut, c'mon, shortcut outta here_...

His magic flared but didn't cast. The implant had suppressed his voluntary magic too.

"oh fuck... gaster, get off..."

That tongue licked his neck again, unpleasantly warm and slimy.

"fuck..."

Gaster drew back. They locked eyes and what Sans saw in Gaster's was nothing less than predatory satisfaction. “So good.”

Sans stared him down. "you fucker. let go of me."

"I'm not done yet," he purred, and shrugged off his lab coat.

"what? what?! wait, wait a sec, gaster, back up a little..."

Gaster's coat hit the floor and he got up on the table, straddling Sans's body. Sans needed to squirm, had to buck him off, but could do nothing but lie there like a lifeless doll. The weight of Gaster's body on his own made him feel sick. "get off me..."

Gaster pulled off his gloves, balled them up and tossed them aside. He slid his bare hands over Sans's ribcage, feeling the curvature of every rib. Gaster licked his teeth and Sans saw his tongue hanging there, a bead of purple saliva balling at its tip. Sans couldn't turn his head or close his eyes. He couldn't look far enough away from Gaster's hungry face looming over him.

"So long as my little control device is on, you won't be able to move an inch," Gaster said, and Sans hated the smugness in his voice.

"you put an implant in my soul so you could paralyse me to feel me up?" Sans's voice wavered as he spoke. “you sick fuck.”

Gaster picked up on the emotion in Sans's voice. "There's no use being upset, Sans." He tugged at Sans's rib, making him gasp. "The best part is, we have so much time to mess around... nobody will disturb us in here."

He leaned down and Sans made a noise of disgust, trying to drive him away.

"We have all night." Gaster pressed his tongue to Sans's jaw and dragged it over his teeth. The wet weight made Sans gag in revulsion but he could do nothing but stare and speak.

"g-gaster, come on, stop, th-this isn't right. this is assault, come on, doc, knock it off... you don't want to do this..."

"Don't I?" Gaster gripped Sans's jaw and tugged it ajar, leaving a gap for his tongue to seep in through. Gaster's eyes closed while Sans's eyes were frozen open.

His slimy tongue explored the inside of Sans's mouth, sliding over the bottom and rubbing along every ridge and bone in there. Saliva like warm slime was smeared around the inside of Sans's jaw while Sans could do nothing but groan around his tongue. Gaster had no taste but his breath smelled like his lab -- clean, almost chemical; bitter and sterile. It was like having a wet wad of betadine-soaked leather rubbing around the inside of his jaw.

Finally Gaster's face drew away and his tongue pulled out of Sans's mouth, and Gaster gave his own teeth one last lick to clean off the spit before his magic tongue dissipated.

"Mmm, that was good..." His hands squeezed Sans's ribcage.

"and you'll stop now, right?" Sans heard his voice go an octave higher. "right? you'll let me go?"

Gaster rocked back, his hands letting go of Sans's body.

When Gaster released him, it felt like a nauseating weight had been lifted from his chest. Relief flooded through him. "fuck, gaster, thank you... now get off me, please..."

"I like seeing you beg," Gaster purred, not shifting from his spot straddling Sans's hips. Gaster eyed Sans's body as he reached for his own belt.

"oh no – fuck – no!"

Sans screamed, his voice echoing around the lab.

As his echo faded, silence set in again. They were still alone.

Tears pricked at Sans's wide open eyes. He watched Gaster unbuckle and unzip his pants and a sob choked in the back of his throat. Hearing it, Gaster smiled. He pushed his open pants down just enough to pull out his penis. Sans took one look at the erect purple magic mass and panicked harder. He rolled his eyes up as far as he could so he didn't have to see it. Tears spilled over his cheekbones and down his skull.

"just -- just stop, please," Sans whispered, still looking away at the ceiling, and his breath hitched. "i won't tell anyone, just please, let me go now, i'm begging you... i won't tell anyone. just let me go. _please_."

Bare hands stroked his spine and rubbed his vertebrae. Sans sobbed, feeling pathetic, knowing he could do nothing. It was useless to try to fight Gaster. The hands traveled lower and hooked inside Sans's pants, brushing his pelvis and making him wince. Nobody else had touched there before. Gaster was going to defile him.

" _please_ ," Sans forced out, looking back down at Gaster.

Smirking and holding eye contact, Gaster tugged at Sans's pants until they started to slide down over his legs.

"you can't do this...."

"Oh, I can, Sansy. And, look, I'm doing it." Gaster climbed off the table, and pulled Sans's pants down off his body and dumped them on the floor. Sans's shoes and socks followed. The cold air reaches Sans's legs and pelvis and his sacrum contacted the chilled steel of the table. He wanted to move so fucking bad, just run, just get away from there, but every joint in his body was unresponsive.

Gaster didn't take anything else off himself. His sleeves were rolled up and his dick was sticking out of the front of his pants, but that was all. He retained his dignity and composure while Sans was naked and freezing, laying slack on the table.

"Cold?" Gaster stroked a hand down his sternum. "Don't worry, Sans, I'll warm you up again."

"don't." More tears leaked from his sockets, and his breath hitched with emotion. "please. gaster, just stop."

Gaster touched a finger to his trail of tears, and brought the wet fingertip to his own mouth and sucked it clean. Sans whimpered and tore his eyes away again.

Gaster forced his femurs apart. There was just a bare pelvis. Without his magic activated, Gaster couldn't fuck him. That was the one thing Sans clung to. Sans couldn't be raped, not for real, not fully – not if he didn't summon anything for Gaster.

“You're beautiful.” Those hands stroked his hipbones, down to his pubic crest and over the brim, thumbs caressing in circles. His fingertips scraped around the inside of his pelvis. Sans just had to bear it. Just bear those invasive fingers that made him want to scream. Just bear it until Gaster jerked off his load onto him, or whatever that sick fuck was planning. Gaster couldn't fuck him for real and couldn't keep him here forever, so now all Sans had to do was keep his eyes on the ceiling and wait. “I bet I'm your first.” Gaster fingered the holes in his obturator foremen and rubbed down his pubic arch, taking his time with every spot. “You're a virgin, right? I'll be the man to deflower you.” His cock rubbed against the rim of his pelvis, disgustingly invasive.

Gaster grinded, groped and caressed his body until Sans was a sobbing, heaving mess.

Finally, Gaster rolled his hips back and took his hands away.

 _please be done_ , Sans begged inside his head, too weak to force the words from his mouth. _please just let me go_.

Gaster pulled the little remote out of his pocket.

 _do it, free me_ , Sans begged inside his mind, hope blooming in his gut. _please. oh, please_.

“Here we go...” Gaster clicked a button.

Magic rushed through Sans's body. Feeling euphoric, Sans tried to get up and scramble away, but his hopes were dashed when he realised he still was paralysed. Instead, the magic began to pool in his jaw and pelvis. With growing horror, Sans realised what was happening.

"no... no no no--"

"Yes."

Sans screamed again. But no one came.

Gaster put the clicker away and grabbed Sans's femurs, pulling them further apart. A blue virgin pussy formed between his legs, plump and slick with magic. “Beautiful...”

“fuck...”

“Are you ready?”

Sans wasn't ready. He was sobbing hard, barely able to breathe. Tears ran down his skull.

Gaster rubbed his fingers along his quivering snatch. "A lovely little flower, nice and wet and ready for me." He pushed two fingers inside the slick entrance. Sans mewled at the weird, disgusting sensation.

"What a delightful noise you're making. Let's see what else I can get out of you." He pumped his fingers in and out, stretching him and eliciting whimpers from Sans.

Gaster took his fingers out. He leaned down and pressed his mouth to Sans's jaw again. Their teeth scraped together. His tongue snuck out and lashed across Sans's jaw. Sans was devastated to find a heavy blue tongue forming in response. He couldn't even control the tongue; it was a humiliating, slack, dead weight in his mouth. Gaster forced his own tongue inside to meet his tongue and forced a real kiss on him. Sans choked and gagged in revulsion.

His tongue still assaulting Sans's mouth, Gaster's fingers found and re-entered his pussy, stretching it and hooking around inside to rub its sensitive walls. Sans knew he was stretching his hole to prepare it for Gaster's cock. He was going to be raped.

Gaster's fingers withdrew and so did his tongue, leaving a long strand of purple-blue saliva between their mouths that broke and left a trail of drool on Sans's chin. Gaster licked his own teeth clean and smiled down at Sans.

"Ready, Sweetheart?"

Sans couldn't speak. Gaster took that as a yes.

Gaster lined up his cock and pressed the tip into Sans's tight pussy. It already felt too big, too foreign, too awful to bear. Sans could hardly breathe for crying. Gaster was in Sans's line of sight, and no matter where he looked, Gaster was still there, leering over him. He couldn't not see him.

“Ah...” Gaster hunched over Sans and pushed his cold dick into Sans's warm pussy, all the way in, inch by inch, until it couldn't go in any further. “There we go. Finally.”

He was being violated and attacked with the disgusting sensation of being overfilled with unwanted cock. And there wasn't anything he could do but lie there and take it.

“You're so tight...” Gaster pulled halfway out with slowness that was almost painful. “I knew it, I'm your first.” He thrust his cock back in, hard, making Sans yelp. It didn't hurt – ecto-genitals didn't have any pain sensors – but the fullness was stomach-churning and intense.

Gaster leaned further down and pressed their foreheads together, forcing Sans to meet his eyes. "Fuck, Sans, you're so perfect... such a perfect and tight little pussy..."

He propped himself up, with a hand on the table at either side of Sans's head, and rocked his hips to pull halfway out and thrust in again, hard. His moan synced with Sans's whine of severe discomfort. Gaster started a rhythm, slow but deep, down to the hilt with every thrust.

The twisted sensations and the feeling of being filled, over and over, dominated Sans's mind. He stared past Gaster's head at the ceiling, trying to find a safer place, a happy place in his mind. If he could just tune it out – tune out the quiet moans and grunts above him, tune out the rocking and the filling and the fucking buzz that Gaster was giving him – then he could bear it. But Gaster didn't let Sans dissociate.

Gaster kissed his cheekbone. “Perfect little doll. You feel so good on my cock, sweet little girl.”

He pressed his body flush against Sans's chest, and his tongue pressed into Sans's mouth again for another twisted kiss. Sans's tongue was assaulted again. His jaw ached with the yearning to bite down.

When their mouths parted, the pace became faster and more punishing. Sans made small noises with every thrust. Gaster was moaning and whispering.

"So sweet and tight... I'm going to fuck your brains out... make you scream my name, babydoll... make you all mine..."

“oh god...” Something was rising in his gut. Fuck, he was gonna cum.

Gaster's tongue met his neck and his teeth scraped his vertebrae. For a moment, Sans was convinced he was going to bite down on Sans's spine, but he pulled away.

Gaster moaned. “Sans, little doll, fuck...”

“ah--” The sensation was rising. “no, god, no...”

“Are you going to come, sweeting? Ahh... go on, cum for me.”

Sans's cunt flexed at the brim of his orgasm and he moaned aloud, earning a laugh from Gaster.

“That's right, babydoll. My little toy. Come for me.”

Sans cried out as he came around Gaster's cock and his vision blurred.

The sound devolved into whimpers as the pleasure faded, and then there was nothing but the weight of Gaster's body and the feeling of being violated.

“Sans...”

Gaster moaned as he came, releasing his load into Sans's body with a hard final thrust. Gaster pulled out, breathing heavily.

The liquid trickled from his pussy and Sans gave one final sob before falling silent.

“That was divine... a complete success...”

Sans lay silent and lifeless as a doll on the table. Gaster climbed off him.

“You came, didn't you?” Gaster zipped up his pants. “You enjoy being my toy.”

Still, Sans wouldn't answer.

“I can see you're sulking. Fine, be that way.” Gaster picked up his lab coat and put it on. “You'll warm up to me eventually, my pretty little doll. Goodnight.”

He began to walk away and Sans called out.

“wait – are you just going to leave me here? let me move, already! please... you got what you wanted.”

“You'll stay here until I'm done with you. I'm not quite finished breaking in my new toy just yet.” With that, Gaster walked out, flicking off the lights as he went and leaving Sans naked and alone in the darkness.


End file.
